<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: FeedAbstract.php 19044 2009-11-19 16:44:24Z padraic $
 */

/**
 * @see Zend_Feed_Reader
 */
require_once 'Zend/Feed/Reader.php';

/**
 * @see Zend_Feed_Reader_Entry_Atom
 */
require_once 'Zend/Feed/Reader/Entry/Atom.php';


/**
 * @see Zend_Feed_Reader_Entry_Rss
 */
require_once 'Zend/Feed/Reader/Entry/Rss.php';

/**
 * @see Zend_feed_Reader_FeedInterface
 */
require_once 'Zend/Feed/Reader/FeedInterface.php';

/**
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_Feed_Reader_FeedAbstract implements Zend_Feed_Reader_FeedInterface
{
	/**
	 * Parsed feed data
	 *
	 * @var array
	 */
	protected $_data = array();

	/**
	 * Parsed feed data in the shape of a DOMDocument
	 *
	 * @var DOMDocument
	 */
	protected $_domDocument = null;

	/**
	 * An array of parsed feed entries
	 *
	 * @var array
	 */
	protected $_entries = array();

	/**
	 * A pointer for the iterator to keep track of the entries array
	 *
	 * @var int
	 */
	protected $_entriesKey = 0;

	/**
	 * The base XPath query used to retrieve feed data
	 *
	 * @var DOMXPath
	 */
	protected $_xpath = null;

	protected $_extensions = array();

	/**
	 * Constructor
	 *
	 * @param DomDocument The DOM object for the feed's XML
	 * @param string $type Feed type
	 */
	public function __construct(DomDocument $domDocument, $type = null)
	{
		$this->_domDocument = $domDocument;
		$this->_xpath = new DOMXPath($this->_domDocument);

		if ($type !== null) {
			$this->_data['type'] = $type;
		} else {
			$this->_data['type'] = Zend_Feed_Reader::detectType($this->_domDocument);
		}
		$this->_registerNamespaces();
		$this->_indexEntries();
		$this->_loadExtensions();
	}

	/**
	 * Get the number of feed entries.
	 * Required by the Iterator interface.
	 *
	 * @return int
	 */
	public function count()
	{
		return count($this->_entries);
	}

	/**
	 * Return the current entry
	 *
	 * @return Zend_Feed_Reader_EntryInterface
	 */
	public function current()
	{
		if (substr($this->getType(), 0, 3) == 'rss') {
			$reader = new Zend_Feed_Reader_Entry_Rss($this->_entries[$this->key()], $this->key(), $this->getType());
		} else {
			$reader = new Zend_Feed_Reader_Entry_Atom($this->_entries[$this->key()], $this->key(), $this->getType());
		}

		$reader->setXpath($this->_xpath);

		return $reader;
	}

	/**
	 * Get the DOM
	 *
	 * @return DOMDocument
	 */
	public function getDomDocument()
	{
		return $this->_domDocument;
	}

	/**
	 * Get the Feed's encoding
	 *
	 * @return string
	 */
	public function getEncoding()
	{
		$assumed = $this->getDomDocument()->encoding;
		if (empty($assumed)) {
			$assumed = 'UTF-8';
		}
		return $assumed;
	}

	/**
	 * Get feed as xml
	 *
	 * @return string
	 */
	public function saveXml()
	{
		return $this->getDomDocument()->saveXml();
	}

	/**
	 * Get the DOMElement representing the items/feed element
	 *
	 * @return DOMElement
	 */
	public function getElement()
	{
		return $this->getDomDocument()->documentElement;
	}

	/**
	 * Get the DOMXPath object for this feed
	 *
	 * @return DOMXPath
	 */
	public function getXpath()
	{
		return $this->_xpath;
	}

	/**
	 * Get the feed type
	 *
	 * @return string
	 */
	public function getType()
	{
		return $this->_data['type'];
	}

	/**
	 * Return the current feed key
	 *
	 * @return unknown
	 */
	public function key()
	{
		return $this->_entriesKey;
	}

	/**
	 * Move the feed pointer forward
	 *
	 */
	public function next()
	{
		++$this->_entriesKey;
	}

	/**
	 * Reset the pointer in the feed object
	 *
	 */
	public function rewind()
	{
		$this->_entriesKey = 0;
	}

	/**
	 * Return the feed as an array
	 *
	 * @return array
	 */
	public function toArray() // untested
	{
		return $this->_data;
	}

	/**
	 * Check to see if the iterator is still valid
	 *
	 * @return boolean
	 */
	public function valid()
	{
		return 0 <= $this->_entriesKey && $this->_entriesKey < $this->count();
	}

	public function getExtensions()
	{
		return $this->_extensions;
	}

	public function __call($method, $args)
	{
		foreach ($this->_extensions as $extension) {
			if (method_exists($extension, $method)) {
				return call_user_func_array(array($extension, $method), $args);
			}
		}
		require_once 'Zend/Feed/Exception.php';
		throw new Zend_Feed_Exception('Method: ' . $method
		. 'does not exist and could not be located on a registered Extension');
	}

	/**
	 * Return an Extension object with the matching name (postfixed with _Feed)
	 *
	 * @param string $name
	 * @return Zend_Feed_Reader_Extension_FeedAbstract
	 */
	public function getExtension($name)
	{
		if (array_key_exists($name . '_Feed', $this->_extensions)) {
			return $this->_extensions[$name . '_Feed'];
		}
		return null;
	}

	protected function _loadExtensions()
	{
		$all = Zend_Feed_Reader::getExtensions();
		$feed = $all['feed'];
		foreach ($feed as $extension) {
			if (in_array($extension, $all['core'])) {
				continue;
			}
			$className = Zend_Feed_Reader::getPluginLoader()->getClassName($extension);
			$this->_extensions[$extension] = new $className(
			$this->getDomDocument(), $this->_data['type'], $this->_xpath
			);
		}
	}

	/**
	 * Read all entries to the internal entries array
	 *
	 */
	abstract protected function _indexEntries();

	/**
	 * Register the default namespaces for the current feed format
	 *
	 */
	abstract protected function _registerNamespaces();
}
